Biocidal synergistic compositions for surface and space disinfection

ABSTRACT

A new biocidal composition for surface and space disinfection comprising, an aldehyde and/or dialdehyde, and a phenol derivative in a solvent. In a preferred embodiment, an anionic surface active agent is added to the composition. The phenol derivative can be substituted or unsubstituted and homologs thereof of phenols, quinolinols and naphthols and their salts used alone or in mixtures. The anionic surface active agent can be from the family of alkyl aryl sulfonates or diphenyl oxide sulfonates. The solvent can be water, benzyl alcohol alkanol or mixtures thereof. Said composition is capable of being sprayed or used in an aerosol composition.

United States Patent [1 1 Boucher Nov. 4, 1975 BIOCIDAL SYNERGISTICCOMPOSITIONS FOR SURFACE AND SPACE DISINFECTION [75] Inventor: RaymondMarcel Gut Boucher, New

[21] Appl. No.: 367,124

[52] US. Cl. 424/333; 424/346; 424/348 [51] Int. (11. AOlN 9/24; AOlN9/00; AOlN 9/26 [58] Field of Search 424/333, 45, 258, 346, 1 424/348[56] References Cited UNITED STATES PATENTS 7 3,016,328 1/1952 Pepper etal 424/333 3,057,775 10/1962 Rendon 424/75 3,282,775 1 H1966 Stonehill424/333 3,697,222 10/1972 Sierra 424/333 FOREIGN PATENTS OR APPLICATIONS874,713 7/1971 Canada OTHER PUBLICATIONS N.J., pp. 545, 804 and1060-1061, (1960). McCutcheons, Detergents to Emulsifiers, 1971 annul,Allured Publ. Corp., Ridgewood, N.J., pp. 47-48, (1971).

Chemistry of the Pesticides, D. Frear, C0. Van Nostrand Co., lnc., NewYork, pp. 290-292, 1955.

Primary Examiner-Albert T. Meyers Assistant Examiner-Douglas W. RobinsonAttorney, Agent, or FirmShoemaker and Mattare 57 ABSTRACT A new biocidalcomposition for surface and space disinfection comprising, an aldehydeand/or dialdehyde, and a phenol derivative in ,a solvent. In a preferredembodiment, an anionic surface active agent is added to the composition.The phenol derivative can be substituted or unsubstituted and homologsthereof of phenols, quinolinols and naphthols and their salts used aloneor in mixtures. The anionic surface active agent can be from the familyof alkyl aryl sulfonates or diphenyl oxide sulfonates. The solvent canbe water, benzyl alcohol alkanol or mixtures thereof. Said compositionis capable of being sprayed or used in an aerosol composition.

1 Claim, No Drawings BIOCIDAL SYNERGISTIC COMPOSITIONS FOR SURFACEANDSPACE DISINFECTION BACKGROUND OF THE INVENTION 1. Field of theInvention The present invention contemplates novel and unique biocidalcompositions for surface and space disinfection which are fast acting,stable, having a long shelf life and capable of acting over a widetemperature and pH range. They are capable of being used as sprays or asaerosols released from pressurized containers. These new biocidalcompositions can be usedeither for surface disinfection of medical,dental or surgical instruments and household objects or for spacedisinfection as aerosol cleanser-disinfectants.

2. Description of the Prior Art It has long been known that lowconcentrations of saturated dialdehydes such as pentanedial in thealkaline pH range (R. E. Pepper et al., US. Pat. No. 3,016,328), and inthe neutral or acid pH range (G. Sierra, US. Pat. No. 3,697,222) displayincreasing biocidal activity under the influence of various externalagents such as heat as shown in G. Sierra, Canadian Pat. No. 865,913,cationic compounds as shown in A. A. Stonehill, US. Pat. No. 3,282,775,anionic and non ionic additives as set forth in R. M. G. Boucher, US.Patent application Ser. No. 155,233 or ultrasonics as taught by G.Sierra, Canadian Pat. No. 874,713.

SUMMARY OF THE INVENTION It is accordingly one object of the presentinvention to provide a new biocidal composition for surface and spacedisinfection which is stable having a long shelf life and capable ofacting effectively over a wide range of temperatures and pH.

Another object of the present invention is to provide a new biocidalcomposition which can be used either for surface disinfection ofmedical, dental and surgical instruments and household objects or forspace disinfection as aerosol cleanser-disinfectants.

Yet another object of the present invention is to provide a newsynergistic biocidal composition for surface and space disinfectionwhich acts swiftly at room temperature to kill a wide spectrum ofmicroorganisms such as gram positive and gram negative bacteria,vegetative cells, fungii, viroids, viruses and most bacterial spores.

A further object of the present invention is to provide a newdisinfectant composition comprising an aldehyde or dialdehyde withphenol derivatives, exhibiting a biolethal effect when the chemicals aredissolved in either water or alcohol solutions which may or may notcontain inert fluorocarbons.

' It is also a further object of the present invention to show thatspecific compatible mixtures in the proper ratio of saturated aldehydesor dialdehydes with phenol derivatives and anionic agents can exhibit abiolethal effect especially in a pH range equal to or lower than 7, overa wide-temperature range (20C to 100C), over an extended scale ofdilution (50% chemicals concentrate down to 0.03%) when the chemicalsare dissolved either in water or in an alcoholic solution which may or imay not contain inertfluorocarbons.

-A still further object: of the .present invention is to show that thehereabove. described ternary biocidal 9 with the cell wall physicaldamage action of phenol derivatives. This action can be further enhancedby adding small quantities of fast penetrating anionic surface activeagents.

The dialdehydes or aldehydes which have been found to be effective arethose having from 1 to 8 carbon atoms, among which are methanal,ethanedial, propanedial, butanedial pentanedial, hexanedial, heptanedialand octanedial.

The phenol or phenol derivatives which can be used in the formulationcan have one or several phenol functions and can be simple phenolhomologs, bis-hydroxyphenyl alkanes, halogenated phenol derivatives, dior tri hydric phenols, nitrophenols, amino phenols, quinolinols,naphthols, etc. Derivatives which have proved effective are ortho phenylphenol, paranitrophenol, 2 chloro-4 phenyl phenol, o-benzylp-chlorophenol, ptertiary amylphenol, 2,5 dinitrophenol,chlora-ophenylphenol, 8 quinolinol, 8 quinolinol citrate, 8- quinolinosulfate and o-phenyl phenol sodium salt.

The anionic surface active agents which can be used to enhance thepenetration of the formulation are alkyl aryl sulfonates and diphenyloxide sulfonates.

The solvent is water, benzyl alcohol, alkanol or mixtures of these.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with the presentinvention, there has been found new disinfectant compositions which willkill at room temperature a wide spectrum of microorganisms includinggram positive and gram negative bacteria, vegetative cells, fungii,viroids, viruses and most bacterial spores. These compositions exhibitbiolethal effects over a wide pH and temperature range in concentrationsof from 0.03% to 50% by weight when dissolved in water and/or alcohol.They are effective in a pH range of from 2 to 10 and a temperature rangeof from 20C to C. They are also capable of being mixed with a propellantfor incorporation in an aerosol.

As stated above, the composition can be a binary or ternary composition.The binary composition comprises the synergistic effect of thecombination of from 0.05% to 3% by weight of the composition includingsolvent and propellant, if there be propellant present, of an aldehydeor dialdehyde with from 0.005% to 3% by weight of the compositionincluding solvent and propellant, if there be propellant present, of aphenol. The ternary composition adds to the binary composition of from0.03% to about 2% by weight of the composition including solvent andpropellant, if there be propellant present, of an anionic surface activeagent. The aldehydes or dialdehydes fround to be effective are thosehaving 1 to 8 carbon atoms among which are methanal,

ethanedial, propanedial, butanedial pentanedial, hex-' anedial,heptanedial and octanedial. The aldehyde most preferred, which will beseen from the following tests is pentanedial (glutaraldehyde).

The phenol and phenol derivatives are phenyl phenol, paranitrophenol, 2chloro-4 phenyl phenol, O-benzyl p-chlorophenol, p-tertiary amylphenol,2,5 dinitrophenol, chloro-o-phenylphenol, 8-quinolinol, 8- quinolinolcitrate, 8-quinolinol sulfate and o-phenyl phenol sodium salt.

With regard to the ternary composition, the anionic surface activeagents which are used to enhance the penetration of the formulation are:alkyl aryl sulfonates and diphenyl oxide sulfonates. Two preferredanionic surface active agents are sodium dodecyl diphenyl etherdisulfonate and sodium n-decyl diphenyl ether disulfonate both in liquidform in a concentration of 45%. Some specific examples of thesecompounds are Dowfax 382 registered tradename of Dow Chemical for asodium salt of a C alpha olefin of a diphenyl ether disulfonate andDowfax 2A1 registered tradename of Dow Chemical for a sodium salt of adodecylated diphenyl ether disulfonate. Both compounds contain mono anddialkylated species in a ratio of about 80% to mono-to diand bothproducts are completely sulfonated. These are used in a liquid formhaving a 45% concentration.

The solvent can be water benzyl alcohol or a low molecular weightalkanol or a combination of one or more of the above. The low molecularweight alkanol can be methyl alcohol, ethyl alcohol, isopropyl alcoholor normal propyl alcohol.

When used as an aerosol, a liqified or compressed gas propellant such asisobutane, propane, freon, chlorofluoroalkanes, ethane, carbon dioxide,nitrous oxide or nitrogen can be used with the above composition.

The solvent or solvent-propellant mixture is present in the compositionin an amount of from about 50% to 99.9% by weight of the total weight ofthe entire composition, including the biocidal solution.

To aid in the understanding of the biocidal synergistic effects of thethree different types of chemicals used in the formulation of thepresent invention, hereinafter are reviewed the main bio-physical andbio-chemical mechanisms which take place at molecular level with eachtype of chemical used in the novel formulation.

At the moment it is believed that saturated dialdehydes such asethanedial, propanedial, butanedial or pentanedial producealdehyde-amino reactions with cell proteins (R. M. G. Boucher et al,Proc. West. Pharm. 800., Lake Tahoe, January, 1973). The chemical sitesfor saturated dialdehyde action could therefore involve NH groups,including cross linking reactions between these groups (D. Hopwood,Histochemie; 17-151, 1968), although this does not exclude sites ofaction with other chemical groups (sulfhydryl, hydroxyl, carboxy, etc.).It has been well established that aldehydes (and this is particularlytrue for methanal and pentanedial) have a tendency to form polymers. Inthe case of pentanedial (A. A. Stonehill et al, Am. Journ. Hosp. Pharm.,September, 1963) this chemical loses its biocidal activity when itundergoes polymerization. The rate of polymerization increases with thepH and this limits the use of alkaline pentanedial to two weeks when thesolution is buffered between 7.5 and 8.5. Above pH 9 the polymerizationis extremely fast and this dialdehyde becomes useless as a biocidalagent.

To avoid aldehydes/dialdehydes polymerization new compositions in theacid range have been recently suggested (R. M. G. Boucher, Am. Journ.Hosp. Pharm., August, 1972). Studies conducted with a 220 MHz pro- 4 ton.li'uclear Magentic Resonance Spectrometer at the Ontario ResearchFoundation and in England (P. M. Hardy, et al., chem. Comm. 1969) haveshown that in the case of pentanedial the monomer (suspected to be theonly biocidal agent) is constantly in equilibrium with various types ofpolymers. The polymers formed in the acid range are of the acetal-likestructure and they can revert to the monomer by heating thus explainingthe high biocidal activity disclosed in G. Sierras patent (U. S. Pat.No. 3,697,222). The polymers formed in the alkaline range are of adifferent chemical structure and cannot be reverted to the monomer byheating thus explaining the short biocidal life of alkalineglutaraldehyde solutions.

It has also been recently shown (T. J. Munton et al., J. Appl. Bact.,1972) that at room temperature initial uptake of glutaraldehyde by E.Coli cells are the same in the acid and alkaline range. However, underalkaline conditions the outer layers of the cell are damaged to agreater extent. This could explain why at room temperature alkalineglutaraldehyde is more sporicidal than acid glutaraldehyde. The reversebeing true when the temperature rises. When the external protectivelayer of a microorganism is difficult to penetrate or to combine with,the biocidal effect of the aldehydes/dialdehydes decreases. This is thecase, for instance, of the waxy lipo proteins layer of M. tuberculosiswhich often resists the action of pentanedial. Recent studies by T.Bergan and A. Lystad have shown, for instance, (J. Appl Bact., 1971)that under Kelsey-Sykes procedure 2% alkaline pentanedial is nottuberculocidal.

To improve the biocidal action of dialdehydes the addition of certainsurface active agents (R. M. G. Boucher, U.S. Pat. application Ser. No.155,233), heat (G. Sierra, U.S. Pat. No. 3,697,222) or ultrasonics (G.Sierra, Can. Pat. No. 874,713) have already been suggested. Combiningboth phenolic derivatives and aldehydes or dialdehydes with or withoutanionic detergents is the object of the invention, and we shall showthat it provides unsurpassed results for destroying the toughestMycobacteria at room temperature even when the bacilli are coated withmucous or necrotic caseous substance. This is indeed understandable ifone remembers that fast penetration of the aldehyde radicals throughcell walls is the key to strong biocidal action. The bactericidal actionof phenol depends upon its rendering the cell wall permeable to certainessential cell constituents. This was, for instance, clearlydemonstrated by E. F. Gale and E. S. Taylor (J. Gen. Microb., 1947) whofound that in the case of Streptococcus faecalis a 1% solution of phenolcaused a leak of glutamic acid almost as intensive as produced byboiling. That phenol causes leakage of essential metabolites from thecell was also confirmed by measuring the release of radioactivity fromE. Coli grown on various labeled compounds (J. Judis, Journ. Pharm.Sci., 1963). The biocidal mechanism of phenol agents is not restrictedto cell membrane alteration and as well known, it can also affectbacterial enzymes involved in metabolic phenomena. This has been clearlydemonstrated by D. Bach and J. Lambert (J. Am. Pharm. Assoc., 1937).Studies of these authors on certain dehydrogenases of Staphylococcusaureus showed that a 1:1000 dilution of phenol acting for 30minutesdestroyed the systemsactivating succinate, fumarate, pyruvate andglutamate while the lactate, glucose, formate and butanol systemsexperienced partial inactivation.

The phenol derivatives used in the formula of the invention modify themicroorganisms protective membrane to such an extent that theyfacilitate the penetration of aldehyde/dialdehydes thus promoting afaster 6 It is obvious that other substances may be added to the novelcompositions of the present invention provided they have no detrimentaleffects on the biocidal activity of the compositions. Examples of suchsubkilling rate. This has been observed even with hard to 5 stanceswould be perfumes, odor masking chemicals, penetrate bacterial sporeshaving multilayered coats dyes, pH indicators, anti-corrosion agents,inert fluorocontaining disulphide rich proteins. It has also beenobcarbons for aerosolization and the like. served with the thick cortexlayer containing murein in Having described the modus operandi of thethree bacterial spores. main classes of chemicals used to observesynergistic To further accelerate the diffusion of aldehydel- 10biocidal effects, the following examples and tests will dialdehydes intothe core of protoplast of microorganfurther illustrate the invention.They are given primarisms we successfully added to the aldehyde-dialilyfor the purpose of illustration and should not be condehydes/phenolderivative composition small amounts strued as limiting the invention tothe details given. of synthetic detergents of the anionic type. TheseTable I illustrates five typical compositions of the in- 'agentssuccessfully boosted the lethal effect of our new vention which arecalled A, B, C, D and E. These comcmposition while other non-ionicagents reduced or positions will later be referred to as(A:100 or 8:100,completely destroyed the antimicrobial action of our etc.) when used ata 1: 100 dilution with water or any phenol formulation. In most of ourexperiments synother suitable solvent mixture.

TABLE I Composition Composition Composition Composition CompgsitionComponents in Components in Components in Components in Components inweight weight weight weight weight Pentanedial 2.5 Ethanedial lPentanedial 3 Pentanedial 1.5 Pentanedial 2.5

Para nitro Methanal l 8-Quinolinol 0.5 S-Hydroxyquino-8-Hydroxyquinophenol 1.6 line citrate 1.5 line sulfate 2.5

O-phenyl phenol 0.1 2,4,5, 2

trichlorophenol Sodium n-decyl diphenyl ether disulfonate 45%concentration in Sodium n-decyl diphenyl ether disulfonate 45%concentration in Sodium dodecyl diphenyl ether disulfonate 45%concentration in Sodium dodecyl diphenyl ether disulfonate 45%concentration in liquid form liquid form liquid form liquid form (DOWFAX3B2)* 0.25 (DOWFAX 3B2)* 0.25 (DOWFAX 2A1)* 0.5 DOWFAX 2Al* 2 FragranceFragrance Fragrance 0.1 Fragrance or Fragrance or (essential 011) 0.1(essential oil) 0.1 deodorant 0.2 deodorant 0.1 Soft water 95.45lsopropyl 46.9 Water 96.4 Benzyl alcohol 67 Water 92.9

alcohol Fluorocarbon Propellant (propellant) 28.65 (Fluorocarbon) Water20.1 Water 9.3 Alkalinating (if Agent needed) Trademark of Dow ChemicalCo.

thetic cationic agents such as those mentioned in A. A. To assess thesynergistic, effect of the Formulation A, Stonehills patent (U. 5. Pat.No. 3,282,775) interfered for instance; Mywacleriytm tuberculosis wasChosen with the phenol additive and destabilized the biocidal F F ms 9made P P i gamsm is more resistant to chemical inactivation Composmon'than other vegetative bacteria. The procedure followed was the officialmethod of the Association of Official Of Special interest were thesynthetic anionic detergf x g g g g Pi 3 ou t e 0 101a me o c s or tentest tu es, ig: 2321: 22 g ggfi gggi eF-i gi thirty were used in all theexperiments. Four different h culture media were used which are alldescribed in s all be shown are stable in the acid pH range and theyJAOAC (4 04543 4048 a (2) (4) and (5) Tubes Increase the blo-cldalactivity the aldehyde-dial were incubated at 37C foi' days then examinedfor dehyde/phenol mixture. Sa1d chemicals at a concentrawth Wh Itsdoubtf 1 Smears were tion as low as 0.03% in weight are particularlyefficient 60 gm ere were u in the 2 to 5 pH range. They also greatlyimprove liquid clarity and tolerance of the biocidal mixture to hardwater. It has also been found that the above mentioned syntheticdetergents do not adversely affect the aldehyde-dialdehydes/polymerequilibrium in the neutral and acid pH range.

made from the centrifuged sediment, strained by the Z.N. method andexamined microscopically for acid fast bacilli.

All these tests reported in Table II were conducted at a temperature of20C with a constant exposure time of 10 minutes.

TABLE 11 Tests conducted with Composition A (see Table 1).

Exposure time: 10 minutes at 20C.

Chemical Agents P* (2.5%) An (0.25%) FL (1.7%) P+An P+PL P+An+PL PL+AnCulture Media Pos. Neg" Pos Neg Pos Neg Pos Neg Pos Neg Pos Neg Pos NegProskauer and Beck with and without serum 20 10 30 19 l1 l5 l5 8 22 0 3020 10 Middlebrook's 7H9 Broth l9 ll 30 0 22 8 14 16 10 20 0 30 21 9Dubos Broth with serum 24 6 30 0 14 16 10 20 3 27 0 30 15 15 TB BrothBase without Polysorbate 80 30 0 30 0 5 25 20 10 4 26 0 10 20 P. An andPL mean pentanedial, anionic agent and phenol derivatives. respectively.

"Negative means no growth (i.e. the microorganism has been killed).

TABLE III Composition A (see Table I) 10 minutes at 20C Active chemicalsmeans: dialdehyde phenol derivatives anionic agents.

Dilution of Active Chemicals Composition A Concentration Pos. Neg. l4.45% (weight) 0 30 1:10 0.44 0 30 1:50 0.08 l 29 1:100 0.04 26 4 1:10000.004 30 0 Composition C (see Table l) 15 minutes at 20C Dilution ofActive Chemicals Composition C Concentration Pos. Neg. l 3.5% 0 30 1:100.35 0 30 1:50 0.07 0 30 1:100 0.03 0 30 1:1000 0.003 30 0 Composition E(see Table I) 10 minutes at 20C Dilution of Active Chemicals CompositionE Concentration Pos. Neg. l 7% 0 30 1:10 0.7 0 30 1:50 0.14 0 30 1:1000.07 18 12 1:1000 0.007 30 0 As previously explained, any increase oftemperature will favor the reaction of the pentanedial monomer with cellproteins; and it is also known that Mycobacteria are very sensitive totemperature. It is, therefore, obvious that raises in temperature willonly increase the synergistic mycobactericidal effect. This is clearlyshown in Table IV.

Phenol TABLE IV-continued Tests on a stock culture of BCG (Exposure time5 minutes) *All tests conducted with a ten minute exposure correspondedto no growth (i.e. 30 neg) Trademark of Dow Chemical Co.

Regarding the influence of pH on the compositions of the presentinvention, there are two important facts. As previously stated,commercial pentanedial solutions (50 or 25% concentrate) have a pHcomprised between 2 and 5. In this range they are already highlybactericidal (this includes pseudomonocidal) due to the presence of alarge amount of monomers in equilibrium with reversible monomers. G.Sierra and R. M. G. Boucher (J. Appl. Microb., August, 1971) have shownthat the biocidal activity of aqueous acid pentanedial solutions testedwith wet naked spores of B. subtilis (ATCC 6051) is independent of thepH below 7. It is only in the alkaline range between 7.5 and 8.5 that asurge in biocidal activity (of limited duration in time) is observedbefore the biocidal action sharply decreases (near pH 9). It istherefore obvious that operating in the acid range will not create aproblem with the chosen saturated clialdehydes. Phenols and phenolderivatives are stable in the acid range and generally speaking, theaddition of alkali decreases their germicidal action until a dence (E.J. Ordal et al., J. Bact., 1942). The effect of pH is particularlynoticeable when phenols are solubilized wth alkyl aryl sulfonates. M.Rosein et al. (Farmacia, 1960) have shown with S. aureus a high biocidalactivity at pH 3 when using phenols activated with anionic agents. Touse an example, 2-4-5 trichlorophenol shows a phenol coefficient of 40when tested at pH 6 against S. typhosa'but at pH 10 or higher the phenolcoefficient drops to about 1.

This explains why the formulations of the present invention are veryeffective in the acid range, especially between 2 and 3. 8. All themechanisms involved in the synergistic biocidal effect hereabovedescribed point to a strong microbiocidal action below pH 7. In table Vthere is shown a series of results obtained with composition A and Cwhich confirm the theoretical considerations.

The tests were of the use dilution type and they were performedaccording to the procedure described in the AOAC Methods, 1 ltheEdition, 1970. The stainless 9 steel carriers, free from surfacedefects, were prepared and sterilized according to the directions. The48-54 hours cultures of the various bacteria were grown in nutrientbroth, prepared as directed in 4.001A with Anatone. These were used tocontaminate the cylinders in the manner prescribed. The cultures wereexamined for resistance to Phenol at 20C in each case as directed. Theresistance to phenol was found to exceed the maximum requirements of thetest. As the culture resistance to phenol exceeded the maximumrequirements as to concentration and contact time, each culture used waschecked to show that it was resistant to phenol in the highestconcentration required, and for the maximum time (15' minutes).

The apparatus used for these experiments consisted of an insulated tankequipped with cooling coils and a Heto heating and circulating pump.This enabled the temperature to be controlled to 101C. One contaminatedcarrier was added to 10 cc of composition A at 30 second intervals.Following the contact period the cylinder was subcultured into 10 cc ofsterile fluid Thioglycolate media and shaken. The tubes were thenincubated at 37C for 48hours and examined for growth.

TABLE V Influence Phenol Resistance line range by a proper choice ofchemicals. Composition B shown in Table I is such an example of aformulation with biocidal synergism extended in the alkaline range.

Although conversion of phenol and of the phenol derivatives to thecorresponding sodium or potassium phenates causes a reduction inbactericidal power, the phenates are far more soluble than thecorresponding phenols. Phenates may also act as solubilizers for thephenols. Thus by increasing the soluble amount of biocidal agents, onecompensates for the decreased effectiveness of the phenates. This indeedis well known and explains the wide use of alkaline phenol saltgermicidal formulations. One key novelty of the present invention wasthe discovery that within certain limits of pH (between 7 and 9)mixtures of alkaline phenols do retard the irreversible polymerizationof saturated dialdehydes such as pentanedial and ethanedial. In otherwords, an alkaline pentanedial solution (pl-l 7 to 9) which normallywill start to lose its potency after 2 weeks will retain'it after 1month when mixed with an anionic agent and phenol deravitives. Thisimportant observation makes it also possible to prepare highly potentroom temperature tuberculocidal formulations with a longer life thanthose described in US. Pat. Nos. 3,016,328 and 3,282,775. It alsoenables decreasing Organism. P Cone min min min time for fastmycobactericidal action on highly resisps tant strains. Table VI and VIIprovide pertinent data gf fgg g which clearly establishes the biocidalsynergism of the 15442 2 o 39 compositions of the present invention inthe alkaline 2.6 0 1:80 range.

TABLE VI Aging Tests M. Tuberculosis Test AOAC Sporicidal Test (AOAC at20C) Temperature 60C 20 minutes Solution B. subtilis CI. sporogenesFormulation Age Pos. Neg. Rings Loops Rings Loops Composition A 2 weeks0 30 0/30 0/30 0/30 7 0/30 (adjusted to pH 8*) 4 weeks 0 30 0/30 0/300/30 0/30 7 months 0/30 0/30 0/30 0/30 Alkaline pentanedial 2 weeks l 290/30 0/30 0/30 0/30 (2% sol, pH 8) 4 weeks 8 22 0/30 l/30 0/30 3/30 i 7months 2/30 8/30 3/30 l5/30 With buffering agents 3.7 0 39' 1:80- v t Iv4.7 0 .39- 1:80 I It 1s 1n the acid range (especially between a pH of 22g {528' I to 3.8) that the compositions of the instant invention V L 1are particularlyefficient from the biocidal view point. nuance 9* P P SYF B Q C The choice of the proper phenol derivatives is impor- (10 minuteexposure) 1 1 tant in the acid range due to the relatively poorSOlllbllor anism H i f v 5 zg 'li fi f g ity of phenols in water. One ofthe phenol derivatives g p f 4 which was successfully used in theinstant formulations was the para nitro phenol whose solubility in 100gr of chaleraesuls o (ATCC water at 25 C is close to 1.6 gr. Anotherphenol derlva- 10708) 2 p 0 g 1 38: I I tive which gave excellentresults is 8-Hydroxyquinoline if; 8 2 E or S-Quinolinol which is solublein aqueous mineral 4.7 0 33 1:90 acids. Since the solubility of thischemical is rather g? 3 :38 I i 1 poor innon acidified water there wasused with great success the 8-Hydroxyquinoline citrate which is freelypH adjusted with buffers Table V clearly shows that the synergisticalbiocidal soluble in water. Also of interest was the S-Hydroxyquinolinesulfate which is soluble in water but is diffi-- cult to use in aerosolformulation due to its relatively.

poor solubility in alcohol. The S-Quinolinol derivatives have notoxicityand both the citrate and sulfate do not decrease the biocidalsynergism when added to acid solution of pentanedial or other compatiblesaturated dialdehydes.

12 lecular shape but also its solubility in the solvent used for theformulation.

TABLE VIII CORRESPONDING SOLUBILI'IY IN SPORICIDAU TYPE or ACID ALDEHYDEWATER AT 20C ACTIVITY H-COOH HCHO Methanal FORM IC (Formaldehyde) SOLGOOD HOOC-COOl-I CIHO Ethanedial OXALIC cno (Glyoxal) SOL GOOD cnoHOOCCH2COOH cu. Propanedial MALONIC cno (Malonaldehyde) SOL SL. ACTIVE/cno HOC(CH C0OH(c Butanedial SUCCINIC CI-IO (Succinaldehyde) SOL SL.ACTIVE /CHO nooc cl-i,).,coov ci-i Pemanedlal GLUTARIC \CHO(Glutaraldehyde) s01. EXCELLENT /CHO noocqcmncoorrcmy, l'lexanedlalADIPIC CHO (Adipaldehyde) SL. SOL. SL. ACTIVE HOOC cu cooixcfi $1. $01.v POOR 2 5 2 5 HMEUC \CHO l-leptanedral HOOC-(CH COOH 2)6 Octanedial NOTSOL V- POOR SUBERIC CH0 References to Sporicidal Activity Deal withtests on B. Anthracis, Cl. TETANI, Cl. SPOROGENES. B SUBTILIS and B.PUMILUS IN AQUEOUS AND ALCOHOLIC SOLUTIONS. The names which are notbetween parenthesis have been approved by the International Union ofChemistry TABLE VII AOAC Tuberculocidal test with varying exposure timesat C Note no growth growth It has been established (S. D. Rubbo, et al.,J. Appl. Bact., 1967) that the biocidal effect of saturated dialdehydesis related to the presence of two free reactive aldehyde groups. It is,therefore, obvious that dialdehydes such as propanedial, hexanedial,butanedial, pentanedial, heptanedial, octanedial, etc. can be used toformulate biocidal compositions within the framework of the presentinvention; however, the biocidal effect is dependent not only upon thedialdehyde mo As can be seen in Table VIII, the spori'cidal or biocidalactivity of the various dialdehydes seem to follow the same generaltrend as their solubility in water. As a general but not absolute rule,the biocidal activity decreases when the length of the --CH chainincreases (i.e. when the distance between the two aldehyde radicalsincreases). A maximum of biocidal activity is observed with three CI-Ibetween the two aldehydes. It is to be noted that according to S. D.Rubbo et al. (J. Appl. Bact. 30:1, 78-87, 1967) the presence of twoaldehyde groups is a must to observe any biocidal activity. This hasbeen established in a series of tests shown in Table IX comparing thebiocidal activity of valeraldehyde (pentanal, CH (CI-I -Cl -IO) withpentanedial (CI-IO (CH -CHO) in alcoholic solutions. It has also beenshown by S. D. Rubbo et al. that substitution in the molecule withoutalteration of the aldehyde group, as in the methyl derivative of pentanedial, reduces the rate of kill but does not eliminate the biocidalactivity. Water base formulation sometimes may not allow increasing thedialdehyde concentration up to the level necessary for fast action. Insuch cases, the difficulty could be avoided through the use of loweralkanol solvents such as methanol, ethyl alcohol, or isopropyl alcohol.

TABLE IX Aerosol Germicidal Testing Composition D TABLE IX-continuedAerosol Germicidal Testing* Composition D replacing Composition DPentanedial by (See Table I) Valeraldehyde Trichoplzylon inlerdigitale/30 +/30 To illustrate the importance of the choice of the dialdehyde,S. Rubbo et al. showed that at a pH 8 the time required to inactivate B.anthracis by a factor of was minutes with pentanedial while littleeffect was observed with propanedial, all other experimental conditionsbeing equal. In short, from the data presented in Table VIII one can seethat the aldehydes to be used in the synergistic formulation are mainlymethanal, ethanedial, propanedial, butanedial, pentanedial, andhexaneo'ial for aqueous solutions. When formulating alcoholic solutionsfor aerosol sprays, one could add to the above-mentioned listheptanedial and octanedial.

To further show the effect of the binary composition used as an aerosol,the following tests were made as 14 nols, nitrophenols amino phenols,Quinolinols, naphthols, etc. Phenol derivatives choice will be guided,mainly for acid range formulation, by the solubility of these compoundsin water or dialdehyde solutions. In some cases it will be advisable toincrease the amount of dissolved phenols by adding a certain proportionof alcohols. For the formulations in the alkaline range, it isrecommended to use a slight excess in alkali to form the correspondingphenate which acts as solubilizer.

10 The presence of the anionic agents, diphenyl oxide sulfonates oralkyl aryl sulfonates will also help to adjust phenol concentration atthe proper level. Compositions F and G, given in Table XI, are twoexamples of such a formulation for use in alkaline pH range. Table XII15 shows the biocidal effect produced by the combination of phenolderivatives with pentanedial with and without an anionic surfactant inan alkaline formulation.

Sodium salt of 2 chloro 4-phenyl phenol (Dowcide 4) 4% 4% O-phenylphenol, sodium salt. Tetrahydrate- (Dowcide A) 5% 5% Anionic agent(Dowfax 3B2) 2% none pI-I adjusted between 8 10 Inert ingredients(water,

fragrance, corrosion inhibitor,

shown in Table X. etc-l 77% TABLE X Aerosol Germicidal Testing*Composition C Composition C Composition C (See Table I) (without phenol)(without aldehyde) Salmonella clmleraesuis 0/30 0/30 +/30 Staphylococcusaureus O/30 0/30 0/30 Streptococcus Pyogener 0/30 0/30 +/3OTrichoplzyton interdigitale 0/30 +/3O +l30 0 denotes no growth in 30tests denotes growth in 30 tests "As described in the AOAC. 10th Ed..1965, p. 89, Gerrnicidal Spray Products", the spray was applied to thetest surfaces by holding the container 8 inches away and spraying for 5seconds. Letheen broth subculture medium was used with staphylococcusaureus, salmonella choleraesuis and Sabouraud letheen broth withTrichophyton interdigitale. Trypticase Soy Broth with 10% serum was usedwith streptococcus pyogenes (beta-hemolytic type A).

Regarding the phenol or phenol derivatives to be used in the presentinvention, they can have one or several phenol functions (i.e. freehydroxyl group) and be simple phenol homologs, bis-I-Iydroxyphenylalkanes, halogenated phenol derivatives, di or tri hydric phe- TABLE XIISynergistic Mycobactericidal effect of Formula F AOAC Test Procedure*Formula F Formula F Formula F without phenols without dialdehydes (seeTable XI) Culture Media Pos Neg** Pos Neg Pos Neg Proskauer and Beckwith and without serum 10 6 24 0 30 Dubos Broth with serum 24 6 3 27 030 *10 minute exposure to biocidal solution at 20C (30 test tubes).**Negative means no growth. Synergistic Mycobactericidal effect ofFormula G AOAC Test Procedure*** Formula G Formula G Formula G withoutphenols without dialdehydes (see Table XI) Culture Media Pos Neg Pos NegPos Neg Proskauer and Beck with and without serum 22 8 8 22 0 30 DubosBrowth with serum 23 7 5 25 0 ***l5 minute exposure to biocidal solutionat 20C (30 test tubes).

Because the biocidal synergistic formulations of the present inventionare single phase liquid compositions, they can be used undiluted ordiluted (see Table III) on surfaces or sprayed in aerosol form (seecomposition B and D, Table I). Upon discharge from aerosol pressurizedcans, they will produce either coarse wet sprays or fine dry aerosolmists according to the type of valve and according to the physicalcharacteristics of the propellant gas. As previously shown in Tables IXand X, the highly potent biocidal compositions will exhibit a 100% killboth as surface and space aerosol disinfectants. They will also leave acontinuous thin film on sprayed surfaces which will remain a sufficienttime to disinfect but will not be thick enough to cause spotting.

While not a critical feature of the present invention, best results areachieved when the essential ingredients of the aerosol formulation ofthe present invention are used in the following approximate proportionsby weight:

From 0.05% to about 7% based on the weight of the composition of activematerial said active material being:

a. from 20 to 45% of an aldehyde or saturated dialdehydes.

b. from 15 to 45% of phenol derivatives.

c. from to of anionic surfactants (when present).

The single phase solvent-propellant mixture may approximately correspondto the following composition by weight:

0. water, from 20 to 83% of total weight composition.

d. alcohol such as methyl alcohol, ethyl alcohol, isopropyl alcohol orbenzyl alcohol, from 5 to 70% of total weight composition.

e. a liquified or compressed gas propellant such as isobutane, propane,Freon, chlorofluoromethane and ethane, carbon dioxide, nitrous oxide,nitrogen, etc. The propellant may appropriately be present in a quantityof about 2 to 25% by weight of the total formulation. As a general rule,well known to the man of the art, the relative amounts of said water,alcohol and propellant in the solvent system are such that saidcomposition has a vapor pressure of from to pounds per square inchgauged at 70F.

Several typical aerosol formulations which correspond to the teachingsof the invention are shown in Table XIII.

A comparison between the two formula in the alkaline range confirms thefact that a saturated dialdehyde with 7 carbons is less biocidal thanthe 3 or 4 carbons type. In the acid range, one can see that the 8-Quinolinol citrate is more active than a higher concentration of8-Quinolinol sulfate. One can also see that the ratio of water toalcohol can vary widely without affecting the biocidal activity of ourcompositions as long as the active agents are completely soluble in theproper amount in the solvent system.

TABLE XIII DISINFECTANT FORMULA FOR SYNERGISTIC AEROSOL MIXTURES ActiveAgents Ethyl Freon* Active Agents O-phenyl phenol Na salt 2.5Heptanedial Pentanedial 8 Quinolinol Dowfax 2A1 8 Quinolinol Dowfax 3327.5 65 lsopropyl Ethyl 20 Freon l0 Freon l l 0.5

Pentanedial 8-Quinolinol Citrate Dowfax 2Al Dialdehydes Phenols orPhenol derivative Anionic Agent Solvent System Water Alcohol PropellantInert Ingredients (including buffer) Aerosol Germicidal Efficiencv( Seeanalytical procedure in Table IX) pH of composition lsopropyl A-46 gas"Dichlorodifluoromethane "A mixture of about 87% isobutane and 13%propane, by volume, manufactured by Phillips.

It is also important to note that the compositions of the presentinvention, contrary to pentanedial solu-' tions, are stable over longperiods of time even when stored continuously at temperatures as high as60C. As can be seen in Table XIV, the compositions of the presentinvention retain their biocidal activity after high temperature storageboth in the acid and alkaline pH range. This is an important featurefrom the practical view point since in the past it greatly limited allapplications with pentanedial solutions. As previously mentioned, thebiocidal activity of the formulations described in Stonehills US. Pat.No. 3,282,775, were said to be only 2 weeks when stored at roomtemperature.

TABLE XIV room temperature over a wide pH. The compositions are capableof being used in either a liquid form or as a spray.

Having thus described the compositions of the invention in terms oftheir preferred embodiments as set forth in the descriptions andexamples of the aforesaid specification, it is apparent to those skilledin the art that various changes and modifications can be made in thesecompositions without departing from the spirit and scope of theinvention.

What is claimed is:

1. A disinfectant composition consisting essentially of pentanedial 2.5%by weight, para nitro phenol 1.6% by weight, O-phenyl phenol 0.1% byweight, sodium n- Biocidal activity of solutions stored at 60C.Microorganism: Trichophyton Mentagrophytes ATCC 9533. AOAC TestProcedure, 1 1th Ed., 1970 pl-l one month two months three months twelvemonths Alkaline glutaraldehyde (2%) 8 Composition C with bufier 3.3Composition F 8.5 Composition G 8.5

Note: tests conducted at 20C, no growth, growth decyl diphenyl etherdisulphonate 0.25% by weight and the remainder water.

1. A DISINFECTANT COMPOSITION CONSISTING ESSENTIALLY OF PENTANEDIAL 2.5%BY WEIGHT, PARA NITRO PHENOL 1.6% BY WEIGHT, O-PHENYL PHENOL 0.1% BYWEIGHT, SODIUM N-DECYL DIPHENYL ETHER DISULPHONATE 0.25% BY WEIGHT ANDTHE REMAINDER WATER.